Abstract: In this study,we aimed to explore the effect of nitrogen addition on the root morphological characters of Macleaya cordata in the reclamation area of South Shanxi Coal Mine,and revealed the root growth adaptation strategies of M. cordata under different nitrogen application levels. An experiment of 5 nitrogen addition levels with 0 (CK),75 (N1),150 (N2),225 (N3) and 300 kg·hm^-2 (N4) were carried out successively from year 2020 to 2021 and measure the root morphological parameters and plant height were measured accordingly in growing season. The results showed that:except for the average root diameter and specific root length,all other root indicators of M. cordata were the biggest at the N3 and N4 treatments among the three samples months in 2020;in 2021 the volume and surface area of M. cordata root at CK,N3 and N4 treatment were showed a "V" dynamic pattern with the extension of the sampling months from June to November and the lowest occurred in August. In 2020,the root growth of M. cordata were strongly promoted at N3 and N4 treatments,but that growth promotion was weakened in 2021. The nitrogen flow processes from nitrogen application to soil and its response of M. cordata root system would take a long time. Hence,it is suggested that long-term control experiments should be carried out in the reclamation area to obtain the optimal nitrogen application scheme.

Key words: Nitrogen addition, Root morphological characteristics, Coal mine reclamation, Macleaya cordata

摘要： 为研究氮添加对晋南煤矿复垦区博落回(Macleaya cordata)根系形态的影响,揭示博落回根系在不同施氮量下的生长适应策略。本研究在2020-2021年开展了0(CK),75(N1),150(N2),225(N3)和300 kg·hm^-2(N4)5个氮水平的控制实验,测定根系形态参数和株高等数据。结果表明:2020年3次采样的博落回根系指标,除平均直径和比根长外,均在N3,N4处理下最大;2021年CK,N3和N4处理的博落回根体积、根表面积均随采样月份表现出"V"型变化,最低值出现在8月;2020年N3,N4处理可以快速促进植物根系生长,到2021年N3,N4处理对植物根系生长的促进作用减弱。本研究认为氮添加于土壤,再反馈于博落回根系需要较长时间,建议在该复垦区开展长期控制实验,得出最优施氮方案。

关键词: 氮添加, 根系形态特征, 煤矿复垦区, 博落回